Former FBI Director James Comey delivers his testimony before the Senate Intelligence Committee on the FBI's investigation into the Trump administration, and its possible collusion with Russia during the campaign, in the Hart Senate office Building in Washington, DC, June 8. / AP-Yonhap

By Ko Dong-hwan

Ousted FBI chief James Comey accused American President Donald Trump's White House of lies and defamation Thursday in sworn testimony that plunged his already troubled presidency deeper into peril, according to AFP.

During almost three hours of televised statements, Comey described himself as "stunned" by Trump's "very disturbing" and "very concerning" behavior in several private meetings.

Detailing the talks, Comey said he took notes for fear Trump might "lie" about the unusual encounters.

Comey recalled that during one White House dinner, the president asked him for "loyalty" and to lay off his former national security advisor Mike Flynn ― who is under criminal investigation over his Russia ties ― imploring Comey to "let this go."

Comey indicated that it was now up to a special prosecutor to determine whether that behavior, and his own sacking, constituted an obstruction of justice, a potentially impeachable offense.

"It's my judgment that I was fired because of the Russia investigation," he told senators. "I was fired in some way to change, or the endeavor was to change the way the Russia investigation was being conducted. That is a very big deal."

The White House and Trump's lawyers expressed vindication over some parts of Comey's testimony and lashed out at others.

"I can definitely say the president is not a liar and frankly am insulted by that question," said White House spokeswoman Sarah Huckabee.